1. Field of the Invention
The present invention relates to a gas supply unit for supplying gas to be used in a semiconductor manufacturing process.
2. Description of Related Art
Heretofore, several kinds of corrosive supply gases have been used in a manufacturing process of semiconductors or others. A gas supply unit is used as a part of a gas supply line which supplies the several kinds of supply gases (see, for example, Japanese patent unexamined publication No. 2001-153289).
FIG. 15 is a view showing an example of a conventional gas supply unit 100.
The gas supply unit 100 includes fluid control devices, namely, a hand valve 101, a regulator 102, a pressure sensor 103, a filter 104, an inlet valve 105, a purge valve 106, a mass flow controller 107, and an outlet valve 108, which are connected with piping blocks 109, 110, 111, 112, 113, 114, 115, 116, and 117 each formed with a gas flow passage, constituting a part of the gas supply line for supplying the several kinds of supply gasses. Since such gas supply unit 100 needs no coupling members between the fluid control devices 101-108, a reduced installation area and a shortened passage length can be achieved.
However, the gas supply unit 100 of FIG. 15 has the following disadvantages.
Specifically, in the gas supply unit 100, the fluid control devices 101–108 are mounted on upper surfaces of the piping blocks 109–117 to construct a passage for supply gas. Thus, the filter 104, for example, which is one of the fluid control devices 101–108, has to be connected with two piping blocks 112 and 113. For installation in the gas supply line, the gas supply unit 100 needs an installation space of the fluid control devices 101–108 and the piping blocks 109–117, leading to an increase in occupied area. The number of components such as the fluid control devices 101–108 and the piping blocks 109–117 is large, which would cause a problem of an increase in weight of the gas supply unit 100 itself. In particular, a plurality of the gas supply units 100 are generally used in adjacently arranged rows. The above problems of the occupied area and weight become more marked every increase in number of the gas supply units 100 to be used in the gas supply line.
In the gas supply unit 100, changing the placement of the filter 104 would be troublesome. Specifically, for instance, to change the placement of the filter 104 from an upstream side of the inlet valve 105 to another upstream side of the regulator 102, the conventional gas supply unit 100 needs the following steps of: demounting the regulator 102, the pressure sensor 103, and the filter 104 from the piping blocks 110–113 respectively; displacing the regulator 102 and the pressure sensor 110 downstream and connecting them with the piping blocks 111–113; and then connecting the filter 104 with the piping blocks 110 and 111, thus newly arranging the order of the regulator 102, the pressure sensor 103, and the filter 104. Such changing of the placement would take much time.